SQLiteDataset: Create an SQLiteDataset Object

In dfdb: Access Data Tables in a SQLite Data Base as Pseudo-Dataframes

Description

Create an SQLiteDataset pseudo-data-frame object.

Usage

SQLiteDataset(table, database=paste(table, ".db", sep=""),
	stringsAsFactors=default.stringsAsFactors())
## S3 method for class 'SQLiteDataset'
print(x, ..., verbose=FALSE)
## S3 method for class 'SQLiteDataset'
summary(object, ..., rows)
## S3 method for class 'SQLiteDataset'
close(con, ...)

Arguments

table	the quoted name of a data table in the database.
database	quoted name of the database file in which the data table is located; if missing, a file named table.db (where “table” is the table argument) in the current directory will be assumed.
stringsAsFactors	if TRUE (the default), character variables are treated as factors; the conversion is done when data are retrieved from the data table.
x, object, con	an object of class SQLiteDataSet.
verbose	if TRUE (the default is FALSE), the whole data set is retrieved and printed; otherwise just some information about the data set is printed.
rows	a quoted SQL query to select rows from the data set; if missing, then all rows are retrieved.
...	arguments to be passed down.

Details

The function SQLiteDataset creates a pseudo-data-frame, which then can be used more or less like a data frame. Use close to close the connection to the database containing the data table referenced by the object.

Value

an object of class SQLiteDataset.

Author(s)

John Fox, [e-mail].

See Also

read.db, dbDriver, dbConnect, dbDisconnect, $.SQLiteDataset, as.data.frame.SQLiteDataset

Examples

dr <- dbDriver("SQLite")
tfile <- tempfile()
con <- dbConnect(dr, dbname = tfile)
dbWriteTable(con, "USArrests", USArrests)
dbDisconnect(con)
Arrests <- SQLiteDataset("USArrests", database=tfile)
Arrests
summary(Arrests)
summary(Arrests, rows="Murder > 10")
close(Arrests)

dfdb documentation built on May 2, 2019, 4:58 p.m.